Sources of variation in factor VIII, von Willebrand factor and fibrinogen measurements: Implications for detecting deficiencies and increased plasma levels

Standardized freezing and thawing of plasma samples appears to be indispensable if reliable FVIII results are to be obtained. Because inflammation can potentially mask deficiency states or mimic an increased risk of thrombosis, FVIII, VWF and Fg determinations should be supplemented by measurements of hsCRP.